Delhi Metro is embroiled in a porn site row as couples travelling at night and other times when trains are empty virtually go for sex on trains. The problem is that the clips that were caught on CCTVs inside trains ended up on pornographic websites.

The Delhi Metro Rail Corporation (DMRC) on Tuesday launched an inquiry into allegations that video footage taken from CCTV cameras on trains had been leaked on the Internet.

The videos, which have been uploaded on pornography sites, show couples on Metro trains in "objectionable positions", raising questions over security breach as well as invasion of privacy.

Anuj Dayal, Executive Director (Corporate Communications) DMRC, said, "DMRC is conducting a thorough inquiry into the reports of circulation of objectionable video clips. The Delhi Metro management has taken serious cognisance of these reports and has already reported the issue to the Cyber Crime cell of the Delhi Police. "

The Crime Branch of the Delhi Police have Additional Commissioner of Police (Crime) Ravindra Yadav said: "The Crime Branch has taken suo motu cognisance of the matter and a case under the IT Act has been registered. Further investigations are underway."

Sources in the DMRC said while they were investigating how the the CCTV footage got online, preliminary investigations have raised doubts about the authenticity of the footage.

"According to our initial probe, the clips are probably not from a CCTV camera installed on the Metro trains. In several clips, the noise of the train as well as the announcements during the journey can be heard in the background. The CCTV cameras installed on the train, however, do not record sound," a DMRC official said.

Officials also said some of the clips are over four minutes long, which would be impossible if they came from a CCTV camera installed on the train.

"The length of some of the video clips have also raised questions about their authenticity as they are more than four minutes long. On the Delhi Metro, travel time between stations does not take more than 2 minutes. In the clips, there seems to be no one entering or exiting the Metro compartment," the official said.

While there were also allegations that the videos may have been leaked by the CISF, senior officials said the cameras on board trains are the sole responsibility of the train operators. The footage on the trains are kept for a maximum of a day, they said.